The present invention relates to a magnetic recording and reproducing apparatus and, more particularly, to improve the picture quality by enabling the crosstalk components from the adjacent tracks which leak to a chroma signal on a certain recording track to be extremely preferably eliminated and to provide means which is useful for making it possible to eliminate the guard band on the recording track (high density recording).
In a two-head helical scan type VTR, in order to eliminate the guard band on a recording track and to realize the high density recording, it is necessary to suppress the crosstalk components from the adjacent tracks and to assure a good S/N ratio. For this purpose, the recording azimuth angles of the adjacent tracks are made different and the components of the adjacent tracks are suppressed by the azimuth loss, thereby realizing the high S/N ratio.
The azimuth loss depends on the recording frequency and a sufficiently large effect can be obtained with respect to a frequency modulated luminance signal in a relatively high frequency band. However, the effect is inadequate for a low frequency conversion chroma signal in a relatively low frequency band.
That is, since the luminance signal is written at a relatively high frequency, no crosstalk occurs. However, since the chroma signal is written at a relatively low frequency, there is a fear of generation of crosstalk. Therefore, the invention intends to eliminate the crosstalk regarding the chroma signal.
According to the conventional techniques, with respect to the low frequency conversion chroma signal, the frequencies for the tracks are interleaved such that the difference between the recording frequencies of the adjacent tracks is set to a value which is an odd-number times as large as 1/2 f.sub.H (in the case of the NTSC system), and in the reproducing mode, the adjacent components are eliminated by using a 1 H comb-shaped filter (H indicates one horizontal scan period). This technique has been disclosed in JP-A-53-105123 (JP-B-58-55719) and JP-A-52-48919.
That is, the invention disclosed in JP-A-53-105123 (JP-B-58-55719) relates to a recording and reproducing method of an information signal. According to this method, when a periodic information signal is recorded onto and reproduced from adjacent tracks, it is recorded so that the phase of the information signal is relatively inverted at every predetermined period of the adjacent tracks in the recording mode, and the interference from the adjacent track is eliminated on the basis of the inversion relation of the phases of the reproduced information signals in the reproducing mode.
Further, the invention set forth in JP-A-52-48919 relates to a recording and reproducing system of a color video signal. According to this system, a carrier chrominance signal separated from a color video signal is frequency converted into a low frequency signal and recorded onto a recording medium, the phase of the low frequency conversion carrier chrominance signal to be recorded is shifted in a predetermined direction by an angle of about 90.degree. at a time at every horizontal scan period, the phase shifting directions on the adjacent recording tracks are made different, and the low frequency conversion carrier chrominance signal is recorded, thereby eliminating the crosstalk of the low frequency conversion carrier chrominance signal between the adjacent recording tracks.
Each of the foregoing conventional techniques requires the very high accurate specification with respect to the delay time of a delay line which is used in the comb-shaped filter. A very small delay time difference causes the comb-shaped characteristics to be fairly deteriorated. Thus, there are problems such that the picture quality is deteriorated and the elimination of the guard band on the recording track (i.e., high density recording) cannot be accomplished.